Electrical protective system



L. H. ROVERE ET AL ELECTRICAL PROTECTIVE SYSTEM Novf, 1934.

Filed June l, 1931 2 Sheets-Sheet l 1% di? a@ H4 il Hw H 2,4 Lw

Nov, 6,. 1934- l.. H. ROVERE Er AL l ELECTRICAL PROTECTIVE SYSTEM Filed June l, 1931 2 Sheets-Sheet gin/vento@ H 0 Vere i? 7.5 es

Patented Nov. 6, 1934 UNITED STATES PATENT OFFICE ELECTRICAL PROTECTIVE SYSTEM Lewis H. Rovere, Brooklyn, N. Y., and Phillip H.

A Estes, Rutherford, N. 3., assignors to The Western Union Telegraph Company, New York,

N. Y., a corporation of New York Application June 1, 1931, Serial No. 541,509

6 Claims. (Cl. 178-69) Our invention relates to electrical protective it comprises an alternating current magnet M1, means and particularly to protective means for a direct current magnet M2 and a main armature systems that are subjected to transient disturb- A1 common to both magnets, that is, the armature ances due to their proximity to electrical power A1 is adapted to be operated by either magnet transmission lines. M1 or magnet M2. The armature A1 carries an 60 It is well known to those familiar with the art insulated contact D adapted to cooperate with that when the transmission line conductorsof oneof the contacts C. In addition to the main a communication system are parallel to an elecarmature A1 the relay has an auxiliary armature tric power transmission line, potentials are often al arranged to be operated by the alternating curinduced in the transmission line conductors of the rent magnet Ml. 65 communication system. Such potentials are The auxiliary armatures al, a2 and a3 are conparticularly severe during transient disturbances nected to a common conductor L and the front in the power transmission system, necessitating contacts with which these armatures are adapted the installation of protective devices in the comto cooperate are connected to a common conmunication system to protect its sensitive instruductor N. Each of the direct current magnets 70 ments and translating devices from damage. M2, M4 and M6 has one of its terminals connect- One object of our invention is to provide a proed to the common conductor L and its other tertective means applicable to a communication minal connected to a common conductor Q. The system to be protected characterized by the abiliconductors N and Q are connected to the battery ty of the protective means to ground all the lines B. It will be evident from the foregoing de- 75 of the system upon the occurrence of a transient scription that operation of any one of the auxilidisturbance on any line of the system. ary armatures al, a2 or a3 will effect the ener- Another object of our invention is to provide gization of all of the direct current magnets M2, an improved protective means applicable to a M4 and M6.

communication system to be protected, compris- The protective devices P in each group are in- 80 ing a plurality of relays so interconnected that terconnected by a common conductor, the latter operation of any relay in response to a surge on being designated by the reference characters Kl, one line of the system will effect operation of all K2 and K3. Each of these common conductors the relays to ground all the lines of the system. is connected to the insulated contact D on the In the following description of circuits and ararmature of the respective group relay, and also 55 rangements disclosing our invention we shall refer to one terminal of the alternating current windto the accompanying drawings in which2- ing of the relay. The remaining terminal of the Figure 1 is a diagrammatic view of one embodialternating current winding is connected to the ment of our invention applied to a communication main armature of the relay and to ground.

system comprisinga plurality of lines. The manner in which the hereinbefore de- 90 Figure 2 is a diagrammatic view showing a scribed system operates isasfollows: Assume that modified embodiment of our invention applied to a transient voltage set up in the communicaa communication system. tion system causes the breakdown of the protec- In Figure l the reference numerals 1 to 24 tive device P associated with line 1. Current will designate the lines or conductors of a comow over the common conductor K1 and through 95 munication system which is to be protected the winding of the alternating current magnet against abnormal voltages set up therein by an M1 of relay R1 and over the main armature A1` extraneous source such as a power line (not of this relay to ground. This will operate armashown). Connected with each line of the comture A1, thereby grounding lines l to 8, inclumunication System iS a protective device PWhiCh sive. It will be observed that line 4 is connected 100 may be of any well known type used for the to ground over the insulated contact D and protection of communication circuits. As shown through the winding of alternating current magin Figure 1, the lines are arranged in a plurality net M1.' This provides a holding circuit for the Of gIOllDS. each 0f Which iS COHIOHBd by a glOuD relay R1. Energization of alternating current relay, the latter beine designated by the refermagnet Mi a1so operates the auxiliary armature 105 ence characters R1, R2 and R3. In each group al, thereby establishing an energizing circuit for the lines to be protected are connected to the all the direct current magnets M2, M4 and M6 contacts C of the group relay. in parallel. Energization of magnet M2 produces The relays are all alike so that a description of no effect but energization of magnets M4 and M6 one will suffice for all. Referring to relay R1, operates their respective main armatures A2, A3 110 thereby connecting lines 9 to 24, inclusive, to

ground; A holding circuit is established through' the winding of alternating current magnet M3 and a similar circuit is established through the winding of alternating current magnet M5 and these magnets therefore operate their auxiliary armatures a2 and a3, respectively, but without producing any additional effect. When the abnormal condition has passed, the alternating current magnets M1, M3 and M5 release their respective auxiliary armatures thereby deenergizing the direct current magnets M2, M4 and M6 an-d restoring all the lines totheir original condition. The normal current in the lines will not operate the magnets. v

Although in Figure l we have shown eight lines in each group it is to be understood of course that any desired number of lines may be included in a group.

In the embodiment of our invention illustrated in Figure 2 each relay is provided with two contacts and is therefore adapted to control two lines. One terminal of relay- R1 is` connected to armature A3 of relay R3 and to protective devices Pl and P6. One terminal of relay R2 is connected to armature A1 of relay R1 and to protective devices P2 and P3. One terminal of relay R3 is connected to armature A2 of relay R2 and to protective devices P4 and P5. The remaining terminals of the relays R1, R2 and R3 are connected to ground.

In operation, let it be assumed that upon the occurrence of an abnormal voltage the protective device of line 3 breaks down. This will cause a flow of current through the winding of relay R2 to ground. Relay R2 will operate, thereby grounding line 3 through its own winding thus establishing a holding circuit for itself. Operation of relay R2 also grounds line 4 through the winding of the relay R3. Relay R3 operates and grounds line 5 through its own winding thus establishing a holding circuit for itself. Operation of relay R3 also grounds line 6 through the winding of relay R1. Relay R1 operates and grounds line 1 through its own winding thereby establishing a holding circuit for itself. Operation of relay Rl also grounds line 2 through the winding of relay R2. When the abnormal condition ceases, the relays become dcenergized and release their armatures, thereby breaking the connections to ground and restoring the system to its original condition.

While this invention has been disclosed as embodied in particular forms, it will be evident to engineers that various changes and modifications can be made Within the scope of the appended claims.

What we claim as new and desire to secure by Letters Patent of the United States, isz- 1. In an electrical protective system the combination with a plurality of groups of lines to be protected from voltages set up by an extraneous source, of a protective device connected With each line and means individual to each group responsive to operation of any one ofl said protective devices for connecting all of said lines to ground, each of said means comprising a relay operating to ground the lines of its group and to cause the operation of the relays of the other groups.

2. In an electrical protective system, the combination with a plurality of lines to be protected from voltages set up by an extraneous source, of a protective device individual to each line, a plurality of relays each responsive to the operation of any protective device of a certain group of lines, and inter-connections whereby each relay when actuated operates to cause the operation of the relays associated with all of the other groups of lines.

3. In an electrical protective system the combination with a plurality of groups of lines to be protected from voltages set up by an extraneous source, of a protective device connected with each line and means individual to each group responsive to operation of any one of said protective devices for connecting all of said lines to ground, each of said means comprising a relay operating to ground the lines of its group and electrical interlocking connections between. said relays whereby operation of any relay eiects operation of the other relays.

4. In an electrical protective system the combination with a plurality of linesto be protected from voltages set up by an extraneous source, of a protective device connected with each line and means responsive to operation of any one of said protective devices for connecting all of said lines to ground, said means comprising a plurality of relays each of which controls a group of said lines and an electrical interlock between said relays whereby operation of any relay effects operation of the other relays, said interlock comprising auxiliary windings for each relay and auxiliary armatures for controlling said auxiliary windings.

5. In an electrical protective system the combination with a plurality of lines to be protected from voltages set up by an extraneous source, of a protective device connected with each line and means responsive to operation of any one of said protective devices for connecting all of said lines to ground, said means comprising a plurality of relays each of which controls a group of said lines and an electrical interlock between said relays whereby operation of any relay effects operation of the other relays, said interlock com'- prising an auxiliary winding and an auxiliary armature for each relay and an auxiliary circuit interconnecting said auxiliary armatures and auxiliary windings. A

6. In an electrical protective system the combination with a plurality of groups of lines to be protected from voltages set up by an extraneous source, of a protective device connected with each line and means individual to each group responsive to operation of any one of said protective devices for connecting all of each of said lines to ground, said means comprising a relay operating to ground the lines of its group through its winding for the discharge of voltage induced by said extraneous source thereby maintaining the relay in operation only during the abnormal condition so that the system is automatically restored to normal condition upon the cessation of said condition, and electrical interlocking connections between saidrelays whereby operation of any relay eiects operation of the other relays.

LEWIS H. ROVERE.

s PHILLIP H. ESTES. 

